The present invention generally relates to computers and software operating on computers and, more particularly, relates to systems and methods for tracing, including recording and analyzing, the execution of software programs in real-time, dynamic and run-time operations.
Software debugging is critical for proper operations of software. Debugging is typically a complex task, particularly in complex, multi-threaded, and distributed software program applications. Conventional debugging tools, such as debugger programs included with software compilers and others, are generally not adequate for debugging in many such instances. Moreover, run-time failures of software are often not easily analyzed and detected with enough specificity to allow bug detection and ascertainment with any specificity.
Software bugs fall into at least three different types or classes of errors. These types of bugs include: syntax errors, logical errors, and algorithmic error. Ralston, A. and Reilly, E., Encyclopedia of Computer Science, Third Ed., p.419. Although all of these types of bugs can be complex and hard to detect and fix, logical errors and algorithmic errors can be the most difficult. Conventional debugger software, sometimes referred to as symbolic debuggers and often supplied with compiler programs, is generally helpful with detecting and identifying points at which an executing program halts prematurely or emits wrong answers because of bugs. These conventional debuggers are used primarily by the program developer during software development and testing.
Debugging is typically a time consuming step in software development which is undertaken prior to wide release or use of the program. The aim in debugging with conventional debug tools has been to detect and remedy errors before software has been distributed to end-users for use in applications. Generally, bugs uncovered in release versions of programs are not remediable by the end-user of the program, particularly in software distributed only in object code or other run-time versions. Developers have relied on reproducing reported bugs in the lab and on end-user descriptions and explanations of bug incidences in order to understand and fix the bugs.
Run-time versions of software programs, such as compiled and executable object code applications, have typically been equipped to provide only minimal run-time failure messages and identifiers. For example, a run-time fault in a common application program usually yields only an “error” or “exception” message that can, but does not necessarily, also include a classifier or indicator of the source or location at which the fault results. These messages produced on fault of the typical run-time application are often not very helpful to the user or developer to analyze and determine the source of or reason for the fault. The error messages merely indicate the point of the program at which the fault or bug causes the entire program to cease operations. This point may or may not be the true source of the bug or other fault, and it is often problematic and cumbersome to attempt to trace back through software code to determine the true source from the limited knowledge afforded by the run-time error message.
The various mechanisms and procedures employed in the past to detect, analyze and remedy bugs in software programs have typically been employed only in the program development process. Debugging is not usually performed in distributed, run-time versions of programs, although debug information beyond the minimal run-time error messages, previously described, could be helpful to isolate and fix bugs that inevitably occur even in release and later versions of software applications. One reason that only the minimal run-time error messages have been included in run-time versions of programs has been the desire for speedy and efficient operations of those programs. Conventional debugger tools are typically complex and computing- and time-intensive to operate, and do not lend themselves to ready operation in run-time circumstances. Nonetheless, more extensive and comprehensive debug information could be helpful to remedy bugs in run-time software, if these problems of conventional debuggers are overcome.
Moreover, prior debugging tools have not allowed on-the-fly choice among debug information from the debug steps during run-time execution of program software code being debugged. Conventional debugging tools are cumbersome and time-consuming to execute, therefore, run-time debugging has not been feasible in view of performance impacts to executing programs. Any run-time debugging has been very limited in capability and use, because of these and other problems.
It would be a significant improvement in the art and technology to provide debugging tools and capabilities to production software code, if the impact of those tools and capabilities does not impact or only negligibly impacts run-time performance or operation of the code.